摘要
污水中往往含有较多腐殖质和其前体物质,主要是动、植物残体以及它们被微生物分解后的有机质。腐殖质由胡敏酸(俗称腐殖酸)、富里酸和胡敏素组成,其分子结构主要以芳香环作为骨架,同时存在一定数量的多环环烷烃、含氮杂环,且在芳香环上还含有大量多种含氧官能团,包括羧基、酚羟基等。在污水处理过程中,沉砂池与初沉池可去除少量腐殖质;二级生物处理过程中微生物很难降解腐殖质,它们主要被活性污泥吸附而转移至污泥中;厌氧消化过程中,外源腐殖质沿程可能发生结构和形态变化,腐殖化程度会有所提高,同时还可能会有其前体物或细胞形成少量内源腐殖质生成。腐殖质结构中羧基、酚羟基等官能团会抑制厌氧水解过程,导致甲烷产率降低;原位金属离子可钝化腐殖质活性官能团,屏蔽其抑制水解作用。为此,需要研究污泥腐殖质在厌氧消化过程的演变规律,探知腐殖质化学与光谱特征,特别是羧基与酚羟基含量变化特征。
There are often more humic substances and their precursors in wastewater： animal and plant residues as well as their residual organic matters after microbial decomposition. Humic substances are usually indentified as humic acids,fulvic acids and humin,whose molecular structures are mostly composed of aromatic rings（ as skeletons） containing many different oxygen-containing functional groups like carboxyl and phenolic hydroxyl groups,and there are also some polycyclic naphthenes and nitrogen-containing heterocycles on their structures.During the processes of wastewater treatment,a minor amount of humic substances may physically be precipitated in grit chambers and primary clarifiers. Humic substances are very difficult to be degraded in biological processes by microorganisms and most of them are often adsorbed on surfaces of excess sludge. During anaerobic digestion process,structures and forms of adsorbed humic substances might change as the result of humification,and probably a minor amount of new humic substances could be generated from their precursors or microorganisms. Carboxyl and phenolic hydroxyl groups in humic substances could inhibit anaerobic hydrolysis process,resulting in a less methane production,but the inhibition might be blocked by in-situ metal cations due to passivating these active functional groups. For this reason,it is necessary to study the evolution patterns of humic substances in anaerobic digestion of excess sludge and to explore their chemical and spectral characteristics,especially for revealing contents＇ variation of carboxyl and phenolic hydroxyl groups.
出处
《环境工程学报》
CAS
CSCD
北大核心
2017年第1期1-11,共11页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51578036)
北京市科研基地建设项目(2016)
关键词
污水处理
碳中和
厌氧消化
腐殖质/胡敏酸
官能团
水解抑制
wastewater treatment
carbon neutrality
anaerobic digestion
humic substances/humic acids
functional groups
hydrolysis inhibition
作者简介
郝晓地（1960-），男，博士，教授，研究方向：污水生物脱氮除磷技术、污水处理数学模拟技术、可持续环境生物技术。E-mail：haoxiaodi@bucea．edu．cn 通信作者
